Writing & History. History is impossible without the written word as one would lack context in which to interpret physical evidence from the ancient past. Writing records the lives of a people and so is the first necessary step in the written history of a culture or civilization.
Lesson Summary. In review, chemical energy is energy stored in chemicals'. Energy is 'the ability to do work. Chemical energy is a type of potential energy that is energy due to the position of an object or objects.
activation energy. activation energy, in chemistry, minimum energy needed to cause a chemical reaction. A chemical reaction between two substances occurs only when an atom, ion, or molecule of one collides with an atom, ion, or molecule of the other.